Vertical GaN power devices

Vertical power devices have advantages to achieve high breakdown voltage and current levels without enlarging the chip size as well as to gain a high reliability by moving the peak electric field away from the surface. We aim at development of GaN-on-GaN unipolar and bipolar diodes and vertical transistors for middle voltage range (600 V – 2 kV). Technological issues such as growth of low-dislocation-density thick GaN with low background doping, controlled n-type and p-type in-situ and ex-situ doping, and device processing will be explored. Device performance simulations will be used for the design and thermal management of the device structures.

Lateral HEMTs for high frequency and power applications

IR-image of a multifinger GaN HEMT fabricated and measured at Chalmers

In this project we will explore new approaches in the overall design of HEMTs for high frequency and power applications. Not only frequency and power capability are in focus, but also other parameters that are important in microwave and power systems, such as flicker noise and linearity. New III-nitride semiconductors, epitaxial structures, as well as devices are designed, grown, and evaluated at material and device level. The device performance is designed and evaluated from an application relevant standpoint.

MMIC technology

In this project we explores advanced concept of integration of GaN HEMTs for high frequency and low power electronics. A base line technology of microstrip MMIC with GaN transistors (HEMTs) and diodes is to demonstrate circuit functionality for novel material and device concepts developed in the “Lateral HEMTs for high frequency and power applications”-project. Furthermore, the density of integrated circuit are increased by investigating multilevel MMIC based on spin on dielectrics (eg. BCB) and circuitry on the backside, which requires hot-via signal paths.